The ruminal biohydrogenation of c9,c12-18:2 can be affected by the fibre/starch ratio of the diet and the ruminal pH. The objectives of this study were to examine independently in vitro the effects of fermentation substrate (hay vs. corn starch) and buffer pH (6 vs. 7) on the biohydrogenation of c9,c12-18:2 carried out by grape seed oil, focusing on its t11 and t10 pathways, using 6-h ruminal i...

Problem statement: Dried tomato pomace may be considered as an alternative feedstuff in ruminant nutrition. The limited literature data that are available so far may be interpreted as indirect and suggestive evidence for diminished ruminal fermentation and bacterial synthesis after substitution of dried tomato pomace for soybean meal. Approach: Rumen-fistulated beef steers were used to address ...

A metabolism study was conducted to evaluate ruminal fermentation and apparent total tract digestibilities of cattle finishing diets. Holstein steers (n = 16, 351 kg of BW) with ruminal cannulas were fed diets consisting of 0 or 25% dried corn distillers grains (DDG), using dry-rolled corn (DRC) or steam-flaked corn (SFC) as the principal energy source (2 x 2 factorial arrangement). The study w...

In a diurnal study, feedstuff and digesta polysaccharides, ruminal bacterial carbohydrate-fermenting groups, and selected ruminal fluid characteristics (ruminal pH, ammonia and volatile fatty acids) were measured in ruminal-cannulated Holstein steers fed high- or low-forage diets at maintenance level intake once daily. A procedure for the sequential extraction of soluble sugar, starch, pectin, ...

The aim of the current study was to evaluate the replacement effect of soybean meal (SBM) at different levels (0 as D1, 33 as D2, 67 as D3 and 100% as D4 based on crude protein (CP) content) by guar meal (GM) on ruminal gas production kinetics, ruminal digestibility and fermentation characteristics of a fattening diet for lambs. Three experiments were conducted. The first experiment of 144-h in...

It is well known that rumen fermentation processes play a key role in ruminant nutrition, as it is this distinctive symbiotic feature between the host and the rumen microflora that lends the ruminant animal several advantages in digestive and metabolic processes over non-ruminants. The extent of complexity of interactions between diverse groups of microorganisms which inhabit the rumen is such ...

Background: Aflatoxins are fungal secondary metabolites negatively affecting ruminant performance; however, little information is available on their impact on rumen fermentation. Aims: This study aimed at determining the effects of different concentrations of aflatoxin B1 (AFB1) from Aspergillus flavus on in vitro gas production and ruminal fe...

The objective of this study was to evaluate the in vitro effects of coconut materials on ruminal methanogenesis and fermentation characteristics, in particular their effectiveness for mitigating ruminal methanogenesis. Fistulated Holstein cows were used as the donor of rumen fluid. Coconut materials were added to an in vitro fermentation incubated with rumen fluid-buffer mixture and timothy sub...

Effects of harvesting ruminal micro-organisms from ruminal ̄uid on patterns of gas production were investigated in experiment 1 by incubating 200 mg DM of pure cellulose, oatfeed, ryegrass, cocksfoot, wet and dry season kikuyu grasses with either diluted ruminal ̄uid or harvested ruminal bacteria. Gas production degradability parameters obtained from ®tting the data to the model Gas ˆ B(1ÿ expÿ...

As a primary energy source for ruminants, volatile fatty acids (VFA) have been estimated to provide up to 75% of the total metabolizable energy (Bergman, 1990). Thus, it is not surprising that diets promoting fermentation and greater production of VFA also promote greater levels of productivity (e.g. milk production) than less fermentable diets (Kolver and de Veth, 2002; Oba and Allen, 2003a,b)...